The present disclosure relates generally to well logging operations and, more particularly, to an improvement in making ranging measurements using a galvanic tool by reducing the effects of conductive mud.
Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation are complex. Typically, subterranean operations involve a number of different steps such as, for example, drilling a wellbore at a desired well site, treating the wellbore to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
Existing well drilling operations require information on formation characteristics to aid in drilling decisions. Numerous measurement techniques are used, including logging while drilling (LWD), measuring while drilling (MWD), electromagnetic (EM) ranging applications, and wireline. One such measurement technique includes the use of a galvanic tool to take ranging measurements of the surrounding formation. Galvanic tools may include one or more electrodes through which current is injected into and returned from the formation to generate the ranging measurements. During typical operation current should ideally only flow between selected ones of the electrodes. In practice, however, “leakage current” may run through other ones of the electrodes. This may reduce the accuracy of the resulting ranging measurements.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.
Throughout this disclosure, a reference numeral followed by an alphabetical character refers to a specific instance of an element and the reference numeral alone refers to the element generically or collectively. Thus, as an example (not shown in the drawings), widget “12a” refers to an instance of a widget class, which may be referred to collectively as widgets “12” and any one of which may be referred to generically as a widget “12”. In the figures and the description, like numerals are intended to represent like elements.